Charging Leisure Batteries

[vw_liz]

OK, Update 2. It's not good news

Step 3 showed the charging voltage as 12.6. No surprises. But it should be 14v, so the output of the charger is definitely the problem. But what could be causing it???

Step 4 gave me nothing. No reading at all going to the control panel. Now that could be why I am not getting the prongs. It might also be how it is supposed to be on a later model charger, and it only sends the current when the batteries are charged.

Step 5 gives me the same 12.6v.

And step 6 does the same which indicates that it is not a problem with the temp sensor.

I took it apart and it was giving me 700 Ohms which dropped rapidly sat in my palm, so I guess that 500Ohms at 20*C is probably spot on.

The batteries are definitely charging as they were almost flat who I put them in, and now sit at 12.6v unplugged from the mains. I may leave them off the charger for a few days to see if they go flat again. Although I'm not sure if that means they were not fully charged or are not holding a charge.

Not sure what the next step is. Any suggestions?

Good job with the testing and reporting back.

From memory a standing voltage of 12.6v would indicate a fully charged battery but you would need to leave the batteries unconnected to around 24h to measure the standing voltage. The fact that yours measure 12.6v straight after charging says to me they are not fully charged.

Right after a battery has been charging I would expect it to measure much higher (>13v maybe) and drop to the true standing voltage after up to 24hours of no use.

Odd that there is no output on the display line but as you say maybe this is how they suppose to work on later chargers. It also is consistent with the way sidepods works.

It seems that your temperature sensors are working, but I do wonder if maybe later vans use a different value sensor? I have just checked mine and both the battery temperature sensor and the outside temperature sensor are the same part number (357 919 379).

If someone out there has a late t4 westfalia could you check what part number is on your sensor?

It may be that if you put a newer charger on an older van you also should change the sensor?

Next steps? This is what I would do...

First I would try swapping the outside temp sensor with the battery one and see if there is any change to the voltage when on charge. The outside one is very easy to get to, it's just behind the front bumper...



Next I would try heating/cooling the sensor while on charge. Cooling (with ice or a fan?) would probably give the most interesting result as I would expect the output voltage to rise as the resistance increases/sensor gets cooler.

Next I would connect to the mains with the temp sensor removed.....I would expect this to force the charger to output it's maximum charge voltage but do this at your own risk! I personally don't think running the charger without the sensor would cause any short term problems but remember this advise is coming from a man without a westfalia charger so I have no way of knowing what will happen!

Good luck!

Jim

 

[vw_liz]

How is your panel wired up? Mine goes from the panel to a regulator in the rear cupboard (the one with the speakers) and from there directly to the batteries.

Yes, that's how mine is done and was how the instructions indicated it should be done.

I think you may be right that charger is switching (cycling) itself on and off. My guess is that it is reading the battery voltage (because of the active panel) at say 15v, so it thinks it is not required, although I'm not sure why then it comes back on a few seconds later.

Does it switch every 3 seconds of is it more random? It could be that when clouds pass overhead, the panel outputs less so the charger takes over? On my regulator I can see the voltage led light and dim and light again as clouds pass overhead!

Jim

 

[vw_liz]

Jim,

I think we need to award you a couple of "bobble hat" icons
for your immense battery charging knowledge.

S.

Haha! Cheers sidepod. (I think!?!), I will wear them with pride!

As with all internet gained knowledge though, I will have probably forgotten it all by next week!

Jim

 

[sidepod]

All this talk of things Westy, sitting here by the fire nursing a cheeky G+T, wishing we were out in the van..

House bound until the new puppy is allowed out ! Two more weeks.

At least I can hear the gentle hum of the leisure batteries charging in the cellar :lol:

S.

 

[sidepod]

Torbot,

Have you checked the DIP switch on the rear of the control panel? Makes sure it's set for two batteries.
I've no idea for sure but could this affect the output of the charter?

S.

 

[vw_liz]

Torbot,

Have you checked the DIP switch on the rear of the control panel? Makes sure it's set for two batteries.
I've no idea for sure but could this affect the output of the charter?

S.

Good idea, no idea if it would make any difference but would be wise to rule it out!

Jim

 

[torbet]

OK,

Sorry for the delay; busy at work over a few weekends.

So, the final update (for the moment)....

I swapped the temp sensor with the one on the front, but that made no difference. However, I realised that the charger came with a few pièces, which I thought were for wiring up the starter battery. But it turns out one of them was a new sensor. Different part number; in fact Mercedes, rather than VW. Also a different design, so had to fit a new end to the cable by the batteries.

Anyway, I changed that last weekend, and I am now getting 14V+ when plugged in, and after a day or so, 13.8 when I unplug, so everything working well The prongs on the plug appear and disappear at random. I've not yet checked the output voltage of plug 5 to see if that has gone up, but I'm just happy to be able to mains charge.

Many thanks to all, particularly Jim (nee Liz) and Sidepod for the détails. If any of you are ever in need of a place to park up for the night in Paris, I can offer a spot within half a dozen Metro stops of the Arc de Triomphe. Mains water and power included!

Cheers again,

Jim

 

[sidepod]

Good results Jim,

Glad I'm not the only one with "Random plug prongs"

I suspect the Mercedes part no. is to do with Merc buying Westfalia, hence the reason VW now make their own California.

S.